protected function saveAssociation($model, $author)
{
// record wish/author association
$wa = new WishAuthor();
$wa->wish_id = $model->id;
$wa->author_id = $author->id;
$wa->save();
}
public function removeAuthor($author_id)
{
$pk = array('wish_id' => $this->id, 'author_id' => $author_id);
WishAuthor::model()->deleteByPk($pk);
}